The deaths of a South Auckland couple on Friday are being treated as a murder and suicide, police say.

Ramnitesh Avinash stabbed Inayat Kawthar repeatedly in the chest at her flat in Great South Rd, Manurewa, on Friday before fleeing the scene. He was found dead a short time later.

Kawthar was rushed to Middlemore Hospital with critical injuries and died hours later.

The deaths have been referred to the coroner. Avinash was on bail at the time over an earlier incident where he threatened to kill Kawthar.

"The chief coroner has authorised police to confirm that the matter is being dealt with as murder suicide, however police will not make any further comment on circumstances leading up to the deaths as they will be subject to inquest findings," Detective Inspector Dave Lynch said today.

In a statement the Kawthar family said it was a difficult time for them as they went through a private and holy grieving process.

"We are asking that the media respect this process and our privacy at this difficult time," the family said.

They said when the time was right they may speak about the incident.

When the stabbing occurred a neighbour at the Great South Rd apartment block said she heard a scream and within minutes police arrived.

District Courts community engagement director Sonja de Friez said the case was being looked into.

"It's a tragedy whenever a person dies in circumstances where the matter is before the courts.

"In these cases all aspects are reviewed and appropriate action is taken."